Quilting is a special art in the general field of sewing in which patterns are stitched through a plurality of layers of material over a two-dimensional area of the material. The multiple layers of material normally include at least three layers, one a woven primary or facing sheet that will have a decorative finished quality, one a usually woven backing sheet that may or may not be of a finished quality, and one or more internal layers of thick filler material, usually of randomly oriented fibers. The stitched patterns maintain the physical relationship of the layers of material to each other as well as provide ornamental qualities.
Large scale quilting operations have been used for many years in the production of bedding products. Mattress covers, which enclose and add padding to inner spring, foam or other resilient core structure, provide functional as well as ornamental features to a mattress. Mattress covers are typically made up of quilted top and bottom panels, which contribute to the support and comfort characteristics of a mattress, and an elongated side panel, which surrounds the periphery of the mattress to join the top and bottom panels around their edges to enclose the inner spring unit or other mattress interior.
Mattresses are made in a small variety of standard sizes and a much larger variety of combinations of interiors and covers to provide a wide range of support and comfort features and to cover a wide range of product prices. To provide variety of support and comfort requirements, the top and bottom panels of mattress covers are quilted using an assortment of fills and a selection of quilted patterns. To accommodate different mattress thicknesses, border panels of different widths are required with variations in the fill for border panels being less common. Border panels as well as top and bottom panels are usually made in different sizes to accommodate all of the standard mattress sizes.
Mattress covers are usually quilted on web-fed multi-needle quilters. Only one side of the quilted product need be finished for a mattress cover, so one layer of ornamental top goods or ticking is usually combined on a chain stitch quilting machine with fill and backing material to produce the mattress cover products. The ornamental characteristics of the ticking that form the outer surface of a mattress is regarded as important in the marketing of bedding products. Bedding manufacturers stock a variety of ticking materials of different colors and types, many having different sewn or printed patterns. Maintaining an adequate inventory of ticking requires the stocking of rolls of different widths of materials of different colors and patterns. The cost of such an inventory as well as the storage and handling of such an inventory contributes substantially to the manufacturing cost of bedding products.
Multiple needle quilters of the type illustrated in U.S. Pat. No. 5,154,130, hereby expressly incorporated by reference herein, are customarily used for the stitching of mattress covers. Such quilters include banks of mechanically ganged needles that sew multiple copies of a recurring pattern. Some of these quilted patterns are highly ornate and contribute materially to the appearance of the quilted products, particularly those that are of higher quality and cost, and which are made in smaller quantities. Other quilted patterns, such as simple zig-zag patterns, are more functional, and rely on the varieties of the ticking material for the visual distinctiveness of the product. The varieties of ticking materials include those sewn or printed with different patterns. Printed patterns are usually applied by the ticking supplier and rolls of ticking of each pattern are inventoried by the mattress cover manufacturer.
The ticking materials commonly bear a pre-applied pattern when rolls thereof are loaded onto the quilting machines. Lower cost mattresses are often made by sewing generic quilted patterns onto printed pattern material. However, frequent changing of the ticking material to produce products having a variety of appearances, requires interruption of the operation of the quilting machine for manual replacement and splicing of the material. This adds to labor costs and lowers equipment productivity. Further, the spliced area of the material web which must be cut from the quilted material is wasted. Furthermore, since mattress top and bottom panels are often thicker, and vary in thickness more than border panels, border panels are sometimes quilted on quilting lines that are separate from those used to quilt the top and bottom panels. Since border panels are usually preferred to match the top and bottom panels, the changing of ticking on the top and bottom panel line is almost always accompanied by a similar change of ticking material on the border panel line. Coordination of the two production lines, as well as the matching of border panels with the top and bottom panels, requires well executed control procedures and can lead to assembly errors or production delays.
There is a need in mattress cover manufacturing to improve the productivity and efficiency of making quilted products, particularly mattress covers, having a variety of designs without increasing, or while reducing, production costs.